Tuya recently purged their free trial users. This doesnt do anything other than mean that you need to re-create your dev access in the Tuya IOT site.
proceed to: https://developer.tuya.com/
Click on IOT Platform (or sign in)
This should bring you to the familiar 3 panel interface:
click on the cloud icon to the left:
then, CLOUD SERVICES:
This will bring you to your cloud services page. from there, the first subcategory should be IoT Core, click on VIEW DETAILS:
Finally, run through the application for a free trial. I am missing those screen shots as Ive written this after the fact. If someone can respond with pics of the process, ill put them in line.
There WILL be a short wait while they “review” your application (it took about 10 minutes for me). You can check back to the IoT Core page to see when you’ve been processes and you should see “Your application for extension is approved”.